Crank but No Start troubleshooting

Joined
Jun 25, 2023
Messages
5
98 “Fineline/Centurion” direct drive with MerCruiser 5.7 (carb) comp ski motor.

Getting good crank but no start after sitting for winter. It was winterized by a shop.

My gut tells me it’s a fuel delivery issue because it fires with starter fluid. I tested the fuel pump at the connector and it’s only reading 9-10v during crank. Seems low? Either way, I have a new fuel pump on the way.

Anyone have any secrets or maybe obvious things I’m not thinking of? I’ve had this boat for one season with no issues last year.

I appreciate any help thanks!
 

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dubs283

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Is the battery good/new?

Could be a connection issue

What ignition system do you have?
 
Joined
Jun 25, 2023
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Battery is brand new (installed yesterday after I killed my old one trying to get the boat to start)

I’m not sure what ignition system I have or how I’d find that out, but yes it could very well be a bad connection somewhere.

I can’t find the master ground in the boat but that’s on my list.
 

dubs283

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Show us a pic of your setup along with any serial/model numbers you find
 
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Jun 25, 2023
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First pic is my engine model number. Second is (I think) fuel/oil pressure sensor/switch. Third is my fuel pump. I read 9-10v going to the fuel pump on crank but it seems low. I ordered a new fuel pump but still feel like that’s too low voltage for the pump.

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alldodge

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Your serial number 0L006627 shows a TBV ignition, Merc carb and electric fuel pump

You can hot wire the fuel pump to see if it runs but could also be the oil pressure switch, a ground or corrosion
 
Joined
Jun 25, 2023
Messages
5
Your serial number 0L006627 shows a TBV ignition, Merc carb and electric fuel pump

You can hot wire the fuel pump to see if it runs but could also be the oil pressure switch, a ground or corrosion
I can’t believe I didn’t think of this. I will try tomorrow and see what happens!
 

Scott06

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Apr 20, 2014
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6,440
First pic is my engine model number. Second is (I think) fuel/oil pressure sensor/switch. Third is my fuel pump. I read 9-10v going to the fuel pump on crank but it seems low. I ordered a new fuel pump but still feel like that’s too low voltage for the pump.

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Voltage will drop some during cranking. Are your battery and ground connections clean and tight ? Is battery in good shape ?
 
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